Electric reproducer for phonographs



H. ARMAGNAT AND P. FRELY. ELECTRIC REPRODUCER FOR PHONOGRAPHS.

APPUCATION FILED MAY l9, l9!!- Patented July 12, 1921.

2 SHEETS-SHEET I.

H. ARMAGNAT AND P. FRELY.

ELECTRIC REPRUDUCER FOR PHONOGRAPHS. APPucAHou FILED MAYI9,19I9.

1,384,295; Patented July 1921.

2 SHEETS-SHEET 2- be placed UNITED STATES PATENT OFFICE.

HENRI ARIAGNAT AND PIERRE FRELY, OF PARIS,

, Application filed Kay 19,

mitter and which comprises a vibrating blade 1 placed between the north and south poles of a magnet and determining, by its vibratlon, variations in the induction in the coil a pulsating or alternatlng current is setup, the apparatus belng adapted to upon the arm ofthe talking mathe vibrations ofthe blade being oscillation of this arm under the chine and due to the influence of the needle or style whichfollows the'curve of the sound groove. The pulsating or alternati' current wh ch 1s set up takes the place 0 the acoustic v bration ordinarily produced in talking machines and this pulsatingor alternating current is employed to produce acoustic vibrations in telephone receivers, sound ampl fiers, or loud speaking receivers and the like.

In the accompanying drawing:

Figure 1 is a vertical view of the magnetic transmitter; I

Fig. 2 is a horizontal section along A-B of Fig. 1;

Figs. 3 and 4 are respectivelyan el'evationf view and a plane-view showing azreproduc'er" in combination with a phonographm dlsk.

' A soft-steel bladel is fixed at its lower.

part in a bracket 2 clamped on the arm 3; of the reproducer. fixed in a bracket 4. which'is'connected to the magnet 5 by screws 6. By means of these screws, the blade l'is adjusted-in such a manner as to be equally distant from the poles N and S.

frame 7 executed in a non-magnetic metal surrounds the legs of the magnet 5 and is provided with a screw 8 which enables the adjustment of the distance between the poles N. and S. I A coil 9 surrounds the blade 1 without touching it.

The arm 3 oscillates in a horizontal plane according to the movements transmitted by the style 10 (Figs. 3 and 4).

Specification Letters Patent.

HENRI ABMAGNAT ofa coil whereby f distance from the 'At' its upper part it is ELECTRIC REPRODUCER FOR PHONOGRAPHS.

1919. Serial no. 288,185.

which follows the waves of the line traced on the disk 11.

Owing to its inertia, the magnet cannot follow the oscillations and the blade 1 comes alternately nearer to each one of the poles N and At rest, when everything is properly adjusted, the blade 1 being in the neutral plane of the magnet is not magnetized, but as soon as it magnetized in cillation of the arm varies inthev blade 1 and an electromotive orce is generated in the spool 9.

he electromagnetic apparatus hereinbe- Patented July 12, 1921.

deviates from this axis, it is proportion with the relative isplacement; cons equently owing to the 'os- 3, the magnetic 'flux fore described may located-at a variable rectly above this style, the greatest sensibility is obtained but notable eiforts are excited onthe style wear and the alteration offthe disk are increased. Of course, the sensibility d'e creases when. the distanced (Fig. 3) from the axis of the blade to the style comes nearer to 1' the radius of the arm.

Experience shows that a good' propoirtion' is: v i

:i r. It is very important that the electromagnetic device has a perfect static and dynamic balance relatively tothe blade 1, in such a manner as to avoid any perturbing noises re-' sulting from the friction of the'style in its urrow. In fact, this friction produces vertical vibrations of thest 1e. do not move the bla poles N and S when the device is properl balanced, but they modifythe relative pOSh tion of the blade in respect of the poles when the symmetry is not perfect.

' wing to the elasticity of the blade 1 which connects it to the arm 3, the magnet forms-an oscillating system, the period of which" inust be oscillations which are to be reproduced.

At the extremity opposed to the style 10, the arm 3 (Figs. 3 and 4) is provided with a double joint in such a manner as to follow without notable resistance the movements of the disk. The arm '3 is pivoted by means of a horizontal shaft 12 on a bracket 13 which is .solid with a vertical shank 14, 'rotating freely in a-socket 15.

' This device is intended to be used in the style 10. If a is di-- 10 and consequently the- .These vibrations e 1 relatively to }the greater than the per od of the sin le direction.

case when the recording is made by oscillations parallel to the plane of the disk. A characteristic feature of the invention is to reproduce the movements taking place in a e claim: 1. In a phonograph, a stylus-carrying arm for coaction with a disk, a magnetic-blade having an extremity secured tosaid arm, a permanent magnet secured to the free end of the said blade and arranged with its poles in 'juxtaposition with said blade, and a spool hollow hub in which said blade os-,

the magnet, and a coil secured to said frame and having a hollow core extending therethrough from end to end and through which hollow core said blade extends.

3. In combination with the style carrying arm of a talking machine, a magnetlzable blade having one end secured on said arm, a permanent magnet secured on the free end of said blade and arranged with its poles opposed to opposite sides of said blade, a non-magnetic frame connecting the arms of the magnet, a coil secured to said frame and having a hollow core extending therethrough from end to end and through which hollow core said blade extends, and means to adjust said magnet With respect to the blade to arrange the poles of said magnet equidistant ,from said blade.

In testimony whereof we afiix our signatures.

HENRI ARMAGEA'E PIERRE FEEEY. 

